arch/blackfin/mach-bf561/smp.c

   1 /*
   2  * Copyright 2007-2009 Analog Devices Inc.
   3  *               Philippe Gerum <rpm@xenomai.org>
   4  *
   5  * Licensed under the GPL-2 or later.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/delay.h>
  12 #include <asm/smp.h>
  13 #include <asm/dma.h>
  14 #include <asm/time.h>
  15
  16 static DEFINE_SPINLOCK(boot_lock);
  17
  18 /*
  19  * platform_init_cpus() - Tell the world about how many cores we
  20  * have. This is called while setting up the architecture support
  21  * (setup_arch()), so don't be too demanding here with respect to
  22  * available kernel services.
  23  */
  24
  25 void __init platform_init_cpus(void)
  26 {
  27         cpu_set(0, cpu_possible_map); /* CoreA */
  28         cpu_set(1, cpu_possible_map); /* CoreB */
  29 }
  30
  31 void __init platform_prepare_cpus(unsigned int max_cpus)
  32 {
  33         int len;
  34
  35         len = &coreb_trampoline_end - &coreb_trampoline_start + 1;
  36         BUG_ON(len > L1_CODE_LENGTH);
  37
  38         dma_memcpy((void *)COREB_L1_CODE_START, &coreb_trampoline_start, len);
  39
  40         /* Both cores ought to be present on a bf561! */
  41         cpu_set(0, cpu_present_map); /* CoreA */
  42         cpu_set(1, cpu_present_map); /* CoreB */
  43
  44         printk(KERN_INFO "CoreB bootstrap code to SRAM %p via DMA.\n", (void *)COREB_L1_CODE_START);
  45 }
  46
  47 int __init setup_profiling_timer(unsigned int multiplier) /* not supported */
  48 {
  49         return -EINVAL;
  50 }
  51
  52 void __cpuinit platform_secondary_init(unsigned int cpu)
  53 {
  54         /* Clone setup for peripheral interrupt sources from CoreA. */
  55         bfin_write_SICB_IMASK0(bfin_read_SICA_IMASK0());
  56         bfin_write_SICB_IMASK1(bfin_read_SICA_IMASK1());
  57         SSYNC();
  58
  59         /* Clone setup for IARs from CoreA. */
  60         bfin_write_SICB_IAR0(bfin_read_SICA_IAR0());
  61         bfin_write_SICB_IAR1(bfin_read_SICA_IAR1());
  62         bfin_write_SICB_IAR2(bfin_read_SICA_IAR2());
  63         bfin_write_SICB_IAR3(bfin_read_SICA_IAR3());
  64         bfin_write_SICB_IAR4(bfin_read_SICA_IAR4());
  65         bfin_write_SICB_IAR5(bfin_read_SICA_IAR5());
  66         bfin_write_SICB_IAR6(bfin_read_SICA_IAR6());
  67         bfin_write_SICB_IAR7(bfin_read_SICA_IAR7());
  68         bfin_write_SICB_IWR0(IWR_DISABLE_ALL);
  69         bfin_write_SICB_IWR1(IWR_DISABLE_ALL);
  70         SSYNC();
  71
  72         /* Store CPU-private information to the cpu_data array. */
  73         bfin_setup_cpudata(cpu);
  74
  75         /* We are done with local CPU inits, unblock the boot CPU. */
  76         set_cpu_online(cpu, true);
  77         spin_lock(&boot_lock);
  78         spin_unlock(&boot_lock);
  79 }
  80
  81 int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle)
  82 {
  83         unsigned long timeout;
  84
  85         printk(KERN_INFO "Booting Core B.\n");
  86
  87         spin_lock(&boot_lock);
  88
  89         if ((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0) {
  90                 /* CoreB already running, sending ipi to wakeup it */
  91                 platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
  92         } else {
  93                 /* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
  94                 bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
  95                 SSYNC();
  96         }
  97
  98         timeout = jiffies + 1 * HZ;
  99         while (time_before(jiffies, timeout)) {
 100                 if (cpu_online(cpu))
 101                         break;
 102                 udelay(100);
 103                 barrier();
 104         }
 105
 106         if (cpu_online(cpu)) {
 107                 /* release the lock and let coreb run */
 108                 spin_unlock(&boot_lock);
 109                 return 0;
 110         } else
 111                 panic("CPU%u: processor failed to boot\n", cpu);
 112 }
 113
 114 void __init platform_request_ipi(irq_handler_t handler)
 115 {
 116         int ret;
 117
 118         ret = request_irq(IRQ_SUPPLE_0, handler, IRQF_DISABLED,
 119                           "Supplemental Interrupt0", handler);
 120         if (ret)
 121                 panic("Cannot request supplemental interrupt 0 for IPI service");
 122 }
 123
 124 void platform_send_ipi(cpumask_t callmap)
 125 {
 126         unsigned int cpu;
 127
 128         for_each_cpu_mask(cpu, callmap) {
 129                 BUG_ON(cpu >= 2);
 130                 SSYNC();
 131                 bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
 132                 SSYNC();
 133         }
 134 }
 135
 136 void platform_send_ipi_cpu(unsigned int cpu)
 137 {
 138         BUG_ON(cpu >= 2);
 139         SSYNC();
 140         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
 141         SSYNC();
 142 }
 143
 144 void platform_clear_ipi(unsigned int cpu)
 145 {
 146         BUG_ON(cpu >= 2);
 147         SSYNC();
 148         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (10 + cpu)));
 149         SSYNC();
 150 }
 151
 152 /*
 153  * Setup core B's local core timer.
 154  * In SMP, core timer is used for clock event device.
 155  */
 156 void __cpuinit bfin_local_timer_setup(void)
 157 {
 158 #if defined(CONFIG_TICKSOURCE_CORETMR)
 159         bfin_coretmr_init();
 160         bfin_coretmr_clockevent_init();
 161         get_irq_chip(IRQ_CORETMR)->unmask(IRQ_CORETMR);
 162 #else
 163         /* Power down the core timer, just to play safe. */
 164         bfin_write_TCNTL(0);
 165 #endif
 166
 167 }